There was a period in early June of 2017 in which Pruitt accumulated $90,000 in travel costs (all of which is funded by taxpayer money.) Some of those June flights include a first-class flight from Washington to New York City-approximately a 40-minute flight-that cost $1,641.23.

The agency also has not spelled out the logic behind its rationale for the flights: Why does the EPA think first-class travel is safer than sitting in coach in the first place?

"As such, for every trip Administrator Pruitt submits a waiver to fly in either first or business class", Wilcox said in a statement to Politico.

"We live in a very toxic environment politically, particularly around issues of the environment", said Pruitt, who acknowledged he had just flown first-class from Washington to Boston to reach New Hampshire.

The Environmental Protection Agency says that Scott Pruitt has traveled first-class on flights both domestically and internationally over the past year because it is simply safer for him.

Pruitt cited a lack of "civility" and said "the level of protection is determined by the level of threat". And, so, ingress and egress off the plane. thats all decisions all made by our (security) detail team, by the chief of staff, by the administration.. He has also taken other measures like adding a soundproof $25,000 "privacy booth", allegedly to stop people from eavesdropping on his private conversations and having his office swept for hidden listening bugs for $3,000.

Such travel decisions, coupled with the EPA's tendency not to publicize Pruitt's out-of-town trips, have prompted criticism from Democratic lawmakers and environmental groups, who have questioned not only how much the agency leader's travel is costing taxpayers, but also how much some of Pruitt's trips have to do with the EPA's mission.

"There have been instances, unfortunately, during my time as administrator, as I've flown and spent time, of interaction that's not been the best", Pruitt told WMUR TV in Manchester, New Hampshire.

CBS News has learned that when Pruitt returned home from Milan on June 11, he flew on Emirates Airlines, whose business class cabins are some of the world's most luxurious, complete with an onboard lounge that promises what the airline calls a "truly unique journey". But he said such travel decisions are made by his security detail.

But neither representatives for the EPA nor Pruitt himself in newspaper and television interviews this week have fully disclosed the nature of the threats against him.

According to records, Pruitt has traveled in at least four non-commercial flights totaling $58,000. The EPA has claimed that all of those flights were "necessary and pre-approved by ethics lawyers", TIMEnotes. The office of EPA Inspector General Arthur Elkins said Wednesday it expects to release the results of its investigation by summer. His spokeswoman, Jennifer Kaplan, said that would impair the ability of the inspector general to perform investigations like the one into Pruitt's spending.